Views
6 years ago

Functional analysis of a nitrite reductase promoter from birch in - Elmu

Functional analysis of a nitrite reductase promoter from birch in - Elmu

Functional analysis of a nitrite reductase promoter from birch in -

Plant Science 155 (2000) 141–151 Functional analysis of a nitrite reductase promoter from birch in transgenic tobacco �,�� Abstract Hans Olaf Warning, Wolfgang Hachtel * Botanisches Institut, Uni�ersität Bonn, Karlrobert-Kreiten-Str. 13, D-53115 Bonn, Germany Received 8 December 1999; received in revised form 27 January 2000; accepted 31 January 2000 www.elsevier.com/locate/plantsci Nitrate assimilation is a highly regulated process in higher plants, and the regulatory cues governing gene expression in this pathway include both external and internal factors. In birch (Betula pendula Roth) the expression of nitrate reductase (NR) and nitrite reductase (NiR) genes is co-regulated by light and nitrate at the transcriptional level. In order to identify cis-acting DNA-elements involved in light and nitrate induction of the birch NiR gene, a 0.9 kb 5� flanking region of the NiR gene was isolated, analysed on the DNA level, and the transcription start site was determined. Deletion analysis of the birch NiR promoter region fused to the GUS reporter gene (uidA) in transgenic tobacco (Nicotiana tabacum) revealed the presence of light- and nitrate-responsive promoter fragments. The responsive fragments showed different activities in leaves and roots. Further, gel mobility shift assays using nuclear proteins from leaves detected a specific DNA-binding activity to the sequence between −146 and −267 bp that was induced in darkness and disappeared in the light. The deletion analysis has shown that this region is critical for light inducibility of the birch NiR gene in leaves. © 2000 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Birch (Betula pendula); DNA-binding activity; Light response; Nitrate response; Nitrite reductase; Promoter analysis 1. Introduction Nitrate is the major source of nitrogen available to plants. The assimilation of nitrate involves the following reactions: its uptake from the external medium by specific translocators, its reduction to nitrite in the cytosol by nitrate reductase (NR), the reduction of nitrite to ammonium in the plastids by nitrite reductase (NiR), and the incorporation of ammonium into amino acids by the glutamine synthethase/glutamate synthase cycle. Nitrate assimilation is a highly regulated process, and the � The nucleotide sequence data reported will appear in the EMBL, GenBank and DDBJ Nucleotide Sequence Databases under the accession number AJ242953. �� In memoriam Dr Klaus Brinkmann, Professor of Botany at the University of Bonn, who died on February 11, 2000. He encouraged me (Wolfgang Hachtel) almost 10 years ago to work on molecular aspects of nitrate assimilation in birch. * Corresponding author. Tel.: +49-228-735584; fax +49-228- 731697. E-mail address: unb142@ibm.rhrz.uni-bonn.de (W. Hachtel) 0168-9452/00/$ - see front matter © 2000 Elsevier Science Ireland Ltd. All rights reserved. PII: S0168-9452(00)00211-9 regulatory cues governing gene expression and enzyme activity in this pathway include nitrate, end-products of nitrogen assimilation, light, sucrose, and cytokinins (reviewed in [1]). Whereas the molecular mechanisms underlying the induction of nitrate assimilation in higher plants remain to be elucidated, promoter analyses of the NR genes of Arabidopsis thaliana [2,3]and Betula pendula [4]and of the NiR gene of spinach [5–9], Phaseolus �ulgaris [10] and tobacco [11] have revealed cis-acting DNA elements involved in nitrate induction. While molecular approaches to study nitrate assimilation in plants have focused on herbaceous species, much less is known for woody species. We decided to investigate the nitrate assimilation system of the European white birch (B. pendula Roth) for two reasons: nitrogen has been recognised to be a critical factor in forest ecosystems and world wide forest decline, and B. pendula is involved in forest disease. In birch, the rate of transcription of

Identification of light- and nitrate-responsive regions of the ... - Elmu
Structure and Function of Cytochrome c Nitrite Reductase - KOPS ...
Maturation of the cytochrome cd1 nitrite reductase NirS from ...
Genetic engineering of nitrite reductase gene improves ... - Wdc-jp.biz
Analysis of a ferric leghemoglobin reductase from cowpea (Vigna ...
functional analysis of rice bidirectional promoters - Michigan ...
Functional analysis of genes from Streptomyces griseus involved in ...
Functional analysis of human and chimpanzee promoters - Webmail ...
Cloning of a Novel Antifungal Promoter from Phaseolus vulgaris and ...
from genome sequence to functional analysis and medical ...
Functional analysis of rice HOMEOBOX4 (Oshox4 ... - ResearchGate